The EGR valve reduces emissions by recirculating exhaust gases, which is extremely beneficial for the environment. You may have replaced the old EGR valve after getting the engine light. But the engine light is not going away even after the replacement.
So, what are the reasons behind a replaced EGR valve light still on? Here are five main reasons.
- Wrong EGR valve or faulty installation
- Bad EGR valve position sensor
- EGR passage is clogged
- Loose connectors or faulty wiring
- ECU malfunctioning
Let me discuss these reasons, their symptoms, and solutions in detail. I will also tell you how to reset the light after resolving the issues.
Table of Contents
Replaced EGR Valve Light Still On – Quick Solutions
The following chart contains quick solutions to the reasons mentioned above. Check it out.
| Reasons | Fixes |
|---|---|
| Wrong EGR valve or faulty installation | Check if the EGR valve matches vehicle specifications. Also, review the installation |
| Bad EGR valve position sensor | Replace the faulty sensor |
| EGR passage is clogged | Remove the EGR valve and clean the passageway |
| Loose connectors or faulty wiring | Check the wiring or connectors and replace them if necessary |
| ECU malfunctioning | Reprogram the ECU |
Replaced EGR Valve Light Still On – Step-By-Step Solutions
Before getting into the solutions, you need to understand the detailed reasons and symptoms associated with them.
1. Wrong EGR Valve or Faulty Installation
It is quite possible that you have used the wrong EGR valve in the vehicle. If the valve doesn’t match the OEM specifications or it has been installed incorrectly, it won’t perform as expected.
- Decreased Engine Performance: The engine performance will drop if the exhaust gas isn’t properly recirculated. If you get the code 84 and engine power is reduced, the reason can be something else.
- Higher Emissions: There will be more soot in the exhaust gas, and emission standards will not be met.
- Lower Fuel Economy: Lower performance of the engine will reduce the fuel efficiency of the vehicle.
Steps You Can Take
- First of all, check if the EGR valve is suitable for your vehicle model and manufacturing year.
- Review the installation process to ensure the associated components, such as hoses or bolts, are connected properly. If not, reinstall the valve.
2. Bad EGR Valve Position Sensor
In some models, the sensor is separate from the valve. If the sensor is faulty even after replacement, either too much or too low exhaust gas will enter the engine. This will result in the following conditions.
- Engine Will Stall: If the valve is not fully open, the engine won’t get enough air from the recirculation. As a result, the engine might stall.
- Decreased Acceleration: The acceleration of the vehicle will drop if the valve can’t work properly due to the faulty sensor.
Steps You Can Take
- Plug an OBDII scanner into the OBDII port of your vehicle and check the error codes. Match the code shown on the scanner with the problems mentioned in the user’s manual.
- If the problem is related to the valve position sensor, you need to replace it. Disconnect the battery first. Then, disconnect the electrical connectors and take the valve position sensor out.
- Install a new sensor and connect the wiring. Then, connect the battery.
3. EGR Passage Is Clogged
Carbon buildup and debris can cause the EGR passage to be clogged over time. If the passageway is clogged and you didn’t clean it while replacing the valve, the right amount of exhaust gas can’t enter the engine.
It causes the engine light to come up with the symptoms I mentioned above. Even if the check engine light is not working, you will notice rough idling, loss of power, etc.
Steps You Can Take
- You have to remove the EGR valve to expose the EGR passage.
- Inspect the passage for signs of carbon deposits and debris. Take an EGR cleaner and use it to clean the passage. I suggest using the Valvoline EGR Cleaner. You can also use a wire brush to scrub the deposits off.
4. Loose Connectors or Faulty Wiring
If the connectors aren’t properly attached while replacing the valve or the wiring gets damaged, the new valve won’t work. As a result, the exhaust gas recirculating system will fail, and you will notice a lot of the above symptoms.
Steps You Can Take
- You should inspect the EGR valve wiring and connectors visually. Tighten the connectors if they are loose.
- Also, check the voltage when the valve is open and closed. The voltage should be 0.9V when the valve is closed and 3.9V when the valve is open. If the wiring is damaged and the voltage level isn’t sufficient, replace the wiring.
5. ECU Malfunctioning
The ECU or Electronic Control Unit is the brain of a vehicle. If the ECU is malfunctioning, the valve may not recirculate the exhaust gas properly. As a result, the engine light will turn on, and you will see the above symptoms.
Steps You Can Take
- The first step is to reset the ECU. I will give you a detailed guide on how to reset the ECU below.
- If this doesn’t solve the problem, get the ECU reprogrammed by an experienced technician.
How to Reset the EGR Valve Light?
If you have done all the steps correctly, but the EGR valve light or engine light is still on, you can follow the methods below.
Method 1: Resetting the ECU
In this method, you will disconnect the battery to reset the ECU.
Step 1
Turn the engine off.
Step 2
Disconnect the battery. You should remove the negative cable first. It is a black cable. Then, remove the positive or the red cable.
Step 3
After the battery has been disconnected, the ECU won’t get any power. It will reset the ECU. You should wait for at least 10 minutes before the ECU is reset.
Step 4
While connecting the battery terminals, do the red or positive one first. Then, connect the negative cable.
Step 5
Turn the key on and wait for five seconds. Then, crank the engine, and the EGR valve light should turn off.
Method 2: Clearing Fault Codes
If the previous method doesn’t turn off the valve light, follow this method.
Step 1
Plug an OBDII scanner into the port.
Step 2
Turn the key to the ON position. Don’t start the engine now. The scanner will show the error codes.
Step 3
Go to “Menu” or “Settings” and select the “Clear Codes” option. You may also find “Reset Codes” or “Reset MIL” options. Select the right option and press “OK” to confirm.
Step 4
The ECU will now be reset, and the fault codes will be cleared. So, the valve light will go off.
Conclusion
The engine light or EGR valve light may come up when the EGR valve is faulty. It should normally go off when the valve is replaced. But unusual things can also happen. The replaced EGR valve light still on without any apparent reason.
In that case, you have to check for the signs I mentioned above and take the necessary steps to solve those problems. If fixing the problems doesn’t reset the light, you should do it manually. Resetting the ECU or clearing the fault codes should turn the light off. And you can continue driving the car with peace of mind.
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